AOA Skin Inner Self Eye Primer

Isododecane's role as a solvent makes it a great texture enhancer. It spreads smoothly on skin and does not leave a sticky feeling behind. Isododecane also helps prevent color transfer in makeup products.

Isododecane is not absorbed into skin.

The chemical name for this ingredient is 2,2,4,6,6-PENTAMETHYLHEPTANE.

The CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations.

True allergic reactions are quite rare: a 15-year retrospective study of 6,751 patients found only 0.31% had a positive reaction (and less than half were considered clinically relevant).

It seemed that when sensitization does occur, it's most commonly linked to topical medication (like corticosteroids) and not cosmetics. Allergic contact dermatitis also appears largely limited to individuals with underlying skin conditions.

Overall, propylene glycol is a well-studied ingredient that most people can tolerate without issue.

It plays several roles in a formula:

Typical use levels for this ingredient sit around 1-10% and the Cosmetic Ingredient Review Expert Panel has affirmed safety at concentrations up to 25% in leave-on products.

Multiple assessments have found it to be non-irritating and non-sensitizing to most people.

However, there have been some cases of allergic contact dermatitis in patients with chronically compromised skin barriers.

Cetearyl alcohol has a comedogenic rating of 2 and irritancy rating of 1. Both of these numbers come from the 1989 study that used rabbit ears; a "2" means mildly comedogenic and a "1" means low irritancy.

Here's the catch: rabbit skin is more sensitive than human skin and throws a lot of false positives. A 1996 reappraisal found that ingredients rated 1-2 in the rabbit ear tests are generally safe for humans.

Remember comedogenic ratings are unable to assess the entire formula of a product or how it will react on your skin. Just be sure to patch test if you are unsure about certain ingredients.

This ingredient is not fungal acne safe. Cetearyl alcohol is a fatty alcohol with chain lengths that fall within the range that Malassezia can metabolize.

In this case, the 60 comes from reacting 60 units of ethylene oxide with sorbitan.

Polysorbates are commonly used in medicine and foods.

Safety-wise, the CIR Expert Panel has concluded it to be safe in cosmetics when formulated to be non-irritating and non-sensitizing.

Free stearic acid is a C18 fatty acid that the Malassezia yeast can substrate, so this ingredient may not be fungal acne safe.

Typical use ranges from 0.5-30%. Most leave-on products are in the 1-10% zone.

The 20 ethylene oxide units is well above the PEG-10 threshold and therefore not a food source for Malassezia (it's fungal acne safe).

This ingredient has a comedogenic rating of 2 and an irritancy rating of 3. These numbers come from testing the raw ingredient on rabbit ears and doesn't reflect how it will behave in a finished product.

In practice, this ingredient is a well-tolerated ingredient. The ratings reflect cautious lab conditions and not real-world use. Just be sure to patch test any formulas you feel unsure about.

This ingredient is typically used in concentrations between 1-10%. Studies have found it to be non-sensitizing, non-phototoxic, and non-photoallergenic.

A close cousin of this ingredient is Glyceryl Stearate SE ("self-emulsifying"). This just has a small amount of sodium or potassium stearate added so it can emulsify without a co-emulsifier.

Since this ingredient is an ester of a C18 fatty acid, it may not be fungal acne safe. The Malassezia yeast can potentially metabolize within the C11-C24 range.

Fun fact: The human body also creates Glyceryl Stearate naturally.

Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.

Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.

Some people who are allergic to imidazolidinyl urea also react to diazolidinyl urea. It ranked as the 14th most common allergen in patch tests from 2005–06.

Safety reviews show that at concentrations under 0.5%, the formaldehyde released remains below the accepted safety limit, making it considered safe for cosmetic use.

Ultimately, its safety depends on individual skin sensitivity and personal comfort with formaldehyde-releasing preservatives.

Ci 77891 is commonly found in sunscreens due to its ability to block UV rays.

Synthetically created CI 77492 is considered safer than those naturally found. This is because the synthetically created version may contain less impurities. Iron oxides are generally non-toxic and non-allergenic.

Synthetically created Ci 77491 is considered safer than those naturally found. This is because the synthetically created version may contain less impurities. Iron oxides are generally non-toxic and non-allergenic.